Apparatus for surface drying of wood blocks



D 1943 o. MATTESON ET AL 2,336,110

APPARATUS FOR SURFACE DRYING OF WOOD BLOCKS Filed March 6, 1959 2Sheets-Sheet 1 ill I J E .5

. I a J N Z "1 l m I s 3 I A I .I N T Pomr H. awro/v was: 0. MATTEJ'ON/Nl EN7'0R A TTORNEY D '.7,1943'.' J. o. MATTESON my 2,336,110

APPARATUS FOR SURFACE DRYING OF WOOD BLOCKS Filed March 6, 1939 2Shgets-Sheet 2 24 as 12 r FIG 2 ROBL'AT H GUYTON JEJJE O. MATTESON INVENTOR PEI? A TTORNEY Patented Dec. 7, 1943 4 APPARATUS FOR ISURFACEDRYING WOOD BLOCKS Jesse 0. Matteson and Robert Guyton, Muskegon, Mich.,assignors to The Brunswick-Balke- Collender Company, Chicago, 111., acorporation of Delaware Application March 6, 1939, Serial No. 259,948

3 Claims.

This invention relates to a machine for the extremely quick drying ofthe surface of a block of wood while not actually drying or heating upthe interior of the block.

An important object of this invention is the provision of means wherebythe surfaces of wood blocks may be quickly and thoroughly driedpreparatory to the application of a layer of a protective resinous paintor the like to certain portions of the block, this method of preparingblocks for kiln drying being fully described in United States LettersPatent to McKenzie, Number 2,120,368 dated June 14, 1938.

It has been found that in the coating of certain portions of woodenblocks or billets of wood with protective material, preparatory to kilndrying, that this material will not quickly and satisfactorily adhere tothe desired portions of the blocks if the blocks are in a damp or moistcondition, and of course this particular condition is always present inanyfreshly cut blocks before they are kiln dried.

Therefore it is desirable to have at least the surface of the blocks ina thoroughly dry state, as thereby the protective coating of resinouspaint or the lik will adhere more quickly and thoroughly to the heartand bark faces, which are thus adapted to be protected, with a view topreventing subsequent checking, cracking, or splitting during the dryingoperation.

It has further been found by experience that a quick surface drying ofblocks of this type is important for various reasons, particularly speedin operation, satisfactory coating, and reduction of cost as far as fuelconsumed in drying is conemed.

The machine described in this specification solves these problems in avery satisfactory manner.

It is an object of this invention to provide apparatus for drying thesurface of a block of wood or other material without unduly raising thetemperature or too quickly drying out the interior of the material.

Other and further important objects of the invention will be apparentfrom the disclosures in the accompanying drawing and followingspecification.

The invention, in a preferred form, is illustrated in the drawings andhereinafter more fully described.

In the drawings- Figure 1 is a side elevation of the improved dryingmachine of this invention, parts being broken away to show the interiorconstruction, and other parts being omitted for purposes of clarity.

Figure 2 is a sectional view taken on the line 22 of Figure 1 looking inthe direction indicated by the arrows and showing a wooden block inposition.

Figure 3 is a sectional view on the line 3--3 of Figure 1 looking in thedirection indicated by the arrows, and on a somewhat larger scale thanFigure 2.

Figure 4 is a plan View of the motor and associated parts.

The mechanism shown in the drawings is particularly designed forhandling and drying blocks of wood intended to be made into bowlingpins, and when presented for treatment in the surface dryer they havealready been shaped approximately to their final form, as seen inFigures 2 and 3.

The reference numeral It indicates generally the supporting frame forthe improved pin block dryer of this invention, the frame having at itstop portion a tubular hood or tunnel I 2 preferably made of stainlesssteel or some material which will reflect heat to a suitable extent, andthis hood is somewhat elliptical in cross-section, as shown in Figure 2.The hood includes an inlet portion I4 and an outlet end l6, theseportions being more flattened than elliptical, as indicated in Figure 3.These end portions of the tunnel are downwardly inclined and their openends are below the level of the bottom of the main tunnel so that theflow of air through the tunnel is opposed or retarded, and there is atendency for the heat to be retained therein.

Mounted on suitable sprockets I8 is a conveyor chain 20 which hasafiixed thereon at intervals a plurality of sets or pairs of supports orbrackets 22 which are adapted to retain blocks or billets of Wood 24, asbest shown in Figures 2 and 3. These supports, which are shown asupwardly open forks or cradles, are connected together in pairs bycross-bars 23 which ride along a centrally disposed supporting rail 25having downwardly inclined end portions 21 extending through theterminal sections l4 and I6 of the hood or tunnel; the inclined rails 21and the cross-bars 23 thus serve to dispense with additional guidewheels for the conveyor chains at the ends of the main portion of thetunnel. The chain is driven by a motor 26 through a speed reductionelement 28 and auxiliary chains 30 and 32.

Mounted in the hood I2 is a plurality of resistance heating elements 34held in position by means of insulators or the like 36 and to whichelectric current is applied in any suitable manner. These heatingelements and insulators extend throughout the length of the horizontalportion I2 of the tunnel, and the heat given off by the elements can bedirectly controlled in any suitable manner, Furthermore the speed atwhich the chain 20 travels through the device can also be controlled byregulation of the motor or speed reduction element 28 thereby assuring avery accurate surface drying of wood blocks 24 both as to the amount ofheat applied to the blocks and the time during which they are in thedryer.

to permit them to be coated promptly, and before any further bleeding ofmoisture occurs.

We are aware that many changes may be made and numerous details ofconstruction varied throughout a wide range without departing from theprinciples of this invention, as indicated by the appended claims.

We claim as our invention:

1. An article surface dryer for articles of elongated form comprising ahorizontally extending .tubular hood open at both ends, a conveyorExperiments have been conducted to find the a best possible way ofproducing this desired result most economically and efiiciently.

The best device developed and the one described in this application is adrying tunnel using the highly polished surface of stainless steel as amirror to reflect back the heat and also to reflect back the red-rayfrom the heating element. the heating elements just under a cherry redcolor their temperature is approximately 1300 F., and the generaltemperature in the tunnel is in. the neighborhood of 1000 F. The contourof the tunnel is made in such a way that the reflecting power isconcentrated on the ends of the pins because the maximum bleeding ofmoisture occurs at these end grain surfaces. The stainless steel isadapted to take a very high polish and thus becomes an excellentreflector so that with. the tunnel of generally ellipticalcross-section, as shown in Figure 2, its top and bottom surfaces arepractically flat and reflect rays of the heatin element directly againstthe side surfaces of the pin blocks, but the side surfaces of the tunnelare shaped with such curvature as to concentrate and focus the reflectedrays onto the end surfaces of the blocks to provide the high-speeddrying effect needed on these areas. The efficiency of the stainlesssteel as a reflector serves to apply to the blocks a very largepercentage of the heat developed by the heating elements, so that verylittle heat escapes through the metallic Wall of the tunnel, and no heatinsulation is found necessary thereon.

Thus, as the blocks 24 travel through the tunnel with their ends quiteclose to the vertically extending portions of the heating elements -34,the heat emanated directly from said elements, .combined with theradiation reflected by the polished walls of the tunnel, servesto flashoff the moisture at or near the surface of the blocks. The discharge endof the tunnel at [-6 is made quite short so that delivery of the blocksshall be rapid with,

mounted for travel through said hood and including brackets disposed atintervals on the con- .veyor and formed to support the elongatedarticles for travel in positions extending transversely of the directionof travel of the conveyor, heat radiating means mounted Within the hoodat both sides of the conveyor, said hood including side walls havingpolished inner surfaces curved to concentrate reflected radiation uponthe ends of the articles carried on the conveyor.

2. In a surface dryer, a horizontally moving conveyor having bracketsdisposed at intervals on the conveyor and formed to support elongatedarticles to be dried for travel in positions extending transversely ofthe direction of travel of the conveyor, a heat radiating grid mountedat both sides of the conveyor and an enclosing tune nel of approximatelyelliptical cross-section en.- .cornpassing the grid and having a highlypolished inner surface, the top and bottom walls .of said tunnel beingsubstantially fiat and the elliptical curvature of the side Wallsserving to concentrate reflected radiation upon limited areas adjacentthe sides of the conveyor,

3. A surface dryer for elongated wooden articles comprising ahorizontally extending tunnel open at both .ends, a .conveyonmounted fortravel through said tunnel and including mean supporting each articlewith 'its grain extending transversely of the direction of travel andwith its end grain surfaces exposed at the sides of the conveyor, andheat radiatingmeans positioned at bothsides of the conveyorand withinthe tunnel to extend along both sides of .the path .of travel of saidarticles, said tunnel being of approximately elliptical-CI'OSSs-S8Cti01'l including side walls having polished inner surfaces,the elliptical curvature of said surfaces serving tocol centratereflected r,a.-.

diation upon the said end grain surfaces ofthe varticles carried on theconveyor.

JESSE -.O. .MATTESQN. ROBER .GUXTQ

